Menindee Lakes in Conservation Mode as Inflows Dwindle

Menindee Lakes in Conservation Mode as Inflows Dwindle

WaterNSW and the Murray­–Darling Basin Authority (MDBA) this week consulted Lower Darling customers and stakeholders on drought management options to ensure surface water supplies from Menindee lakes to Broken Hill can be assured until at least mid-2019 without significant replenishment inflows into the system.

Yesterday (Tuesday, 22 August) WaterNSW Executive Manager, System Operations Adrian Langdon, with WaterNSW staff and senior staff from the MDBA, met with the Lower Darling customer group, the South-West Water Users, to update the group on the outlook based on existing storage levels and the Bureau of Meteorology (BoM) forecast.

At approximately 38% of capacity or >740 gigalitres (GL) - the Lakes' system is holding steady as modest inflows replace water releases and losses to evaporation. Approximately 57GL has flowed into the lakes since May.

However these inflows are currently receding with daily flows rates at Bourke having recently fallen from 500 megalitres (ML) to 400ML/day.

Mr Langdon said the "extremely dry" weather across almost all of regional NSW over June-July was the sole factor inhibiting flows into the Lakes.

Releases from the Lakes are occurring at a rate of 50ML/day from Lake Pamamaroo - which remains at 110% of capacity - and <350ML/day from Lake Menindee, which sits at 5% of capacity.

Significant rain and resulting tributary flows in the Upper Murray are expected to meet downstream and inter-state demand until at least late September/early October, before water will be required from the Lakes, well beyond the previous August estimate.

Even under a very dry scenario WaterNSW will continue releases into the Lower Darling until at least mid-2018.

The BoM is forecasting a median chance of average flows in regional NSW in coming months, though the summer advent of the Queensland storm season typically offers the best chance of significant flows into the upper reaches of the Barwon-Darling system.